Effects of intensive chlorine disinfection on nitrogen and phosphorus removal in WWTPs.

The increased use of disinfection since the pandemic has led to increased effective chlorine concentration in municipal wastewater. Whereas, the specific impacts of active chlorine on nitrogen and phosphorus removal, the mediating communities, and the related metabolic activities in wastewater treatment plants (WWTPs) lack systematic investigation. We systematically analyzed the influences of chlorine disinfection on nitrogen and phosphorus removal activities using activated sludge from five full-scale WWTPs. Results showed that at an active chlorine concentration of 1.0 mg/g-SS, the nitrogen and phosphorus removal systems were not significantly affected. Major effects were observed at 5.0 mg/g-SS, where the nitrogen and phosphorus removal efficiency decreased by 38.9 % and 44.1 %, respectively. At an active chlorine concentration of 10.0 mg/g-SS, the nitrification, denitrification, phosphorus release and uptake activities decreased by 15.1 %, 69.5-95.9 %, 49.6 % and 100 %, respectively. The proportion of dead cells increased by 6.1 folds. Reverse transcriptional quantitative polymerase chain reaction (RT-qPCR) analysis showed remarkable inhibitions on transcriptions of the nitrite oxidoreductase gene (nxrB), the nitrite reductase genes (nirS and nirK), and the nitrite reductase genes (narG). The nitrogen and phosphorus removal activities completely disappeared with an active chlorine concentration of 25.0 mg/g-SS. Results also showed distinct sensitivities of different functional bacteria in the activated sludge. Even different species within the same functional group differ in their susceptibility. This study provides a reference for the understanding of the threshold active chlorine concentration values which may potentially affect biological nitrogen and phosphorus removal in full-scale WWTPs, which are expected to be beneficial for decision-making in WWTPs to counteract the potential impacts of increased active chlorine concentrations in the influent wastewater.

Effect of viscosity on pseudo-Scholte wave propagation at liquid/porous medium interface.

A theory of pseudo-Scholte wave propagating in a saturated porous medium loaded on its interface by a viscous compressible liquid is described. The porous medium is simulated by the Biot theory with high-frequency correction, and the overlying liquid is simulated by the linearized Navier-Stokes equation. An analytical expression for the complex dispersion equation of pseudo-Scholte wave through boundary conditions is established. Then the Riemann sheets related to body waves are discussed and the real and imaginary parts of the complex dispersion equation are separated and solved numerically. The resulting phase velocity, attenuation, as well as displacement and pressure fields are analyzed and comparisons are drawn with the non-viscous model. Finally, a set of parametric analyses is carried out to describe the effects of the phase velocity ratios of the S-wave in the porous medium to Ls-mode in overlying liquid on phase velocity and attenuation of the pseudo-Scholte waves.

[Progress of malaria elimination of Jiangsu Province, China].

There were vivax malaria, falciparum malaria, and malariae malaria epidemic in Jiangsu Province, and vivax malaria was the dominant disease. Anopheles sinensis and An. anthropophagus were malaria-transmitted vectors. Since the founding of People's Republic of China, there have been two major malaria outbreaks in Jiangsu Province, when the highest annual malaria incidence reached up to 24.95%. According to prevention and control principles of "adjusting measures to local conditions, giving different guidance to different categories and highlighting key points", during the epidemic outbreak stage, the largescale malaria prevention and control measures were implemented for all the residents who were target population in Jiangsu malaria-endemic areas. During the basic eradication stage, the targeted prevention and control measures had been carried out according to the different epidemic features to gradually consolidate the achievement of prevention and control in Jiangsu Province. In the malaria elimination stage, Jiangsu Province focused on controlling of the source of infection and malaria surveillance. According to the "1-3-7 targeted elimination" work model, the management of infectious sources and investigation and disposal of foci were carried out for each epidemic focus to block the malaria transmission. By the end of 2017, there had been no indigenous malaria cases for the six consecutive years in Jiangsu Province. All the 13 cities have passed the assessment of malaria elimination of Jiangsu Province. Although Jiangsu Province has achieved the goal of malaria elimination, it is urgent and necessary to maintain and improve malaria surveillance capabilities to prevent malaria reintroduction.

[Vector surveillance in Jiangsu Province during the stage of malaria elimination].

OBJECTIVE: To analyze the vector surveillance results during the stage of malaria elimination, so as to provide the evidence for assessing the local transmission risk of imported malaria and carrying out the surveillance work after malaria elimination in Jiangsu Province. METHODS: From 2011 to 2017, the mosquito population was monitored and human biting rates were calculated by the half overnight human baiting trapping method and overnight lamp trapping method in 7 surveillance sites from June to October. The insecticide resistance level was tested by the force contact method recommended by WHO. RESULTS: A total of 5 106 Anopheles mosquitoes were captured by the half over-night human baiting trapping method in the 7 sites from 2011 to 2017, and all the mosquitoes were identified as Anopheles sinensis. The annual human biting rates were 1.075, 0.786, 1.057, 0.787, 0.790, 1.797 and 1.185 mosquitoes/ (human·hour), respectively. Totally 28 186 Anopheles mosquitoes were caught by the overnight lamp trapping method, and all the mosquitoes were An. sinensis. The densities of Anopheles mosquitoes were 57.950, 50.932, 14.800, 4.405, 58.070, 72.406, and 17.145 mosquitoes/ (night·lamp), respectively. In 2012, the resistance indexes of An. sinensis to deltamethrin, DDT and malathion were at R level in Jiangsu Province. CONCLUSIONS: The major vector is An. sinensis and no An. anthropophagus is found in Jiangsu Province. An. sinensis has a high level of resistance to deltamethrin, DDT and malathion.

[Construction and application of malaria biobank].

OBJECTIVE: To establish a systemized malaria biobank with well-rounded epidemiologic data and a computer-aid management system, thus to provide qualified sources for malaria elimination and human malaria research. METHODS: The malaria biobank was based on the platform of Jiangsu Institute of Parasitic Diseases. The blood smear samples, dried blood samples, whole blood samples and parasite strains isolated from patients (from both local and imported cases) were collected since 2011 according to a standardized operational procedure. The biobank management software was applied to input of the epidemiological data and samples, and the quality of samples was monitored regularly. RESULTS: A standard malaria biobank was established. The Information Management System was applied to input, storage and output of samples. Totally 99.42% (2 223/2 236) of the blood smear samples, 92.58% (2 070/2 236) of the dried blood samples, 94.50% (2 113/2 236) of whole blood, and 2.06% (46/2 236) of the isolated stains in 2 236 reported cases were included in the malaria biobank in Jiangsu Province from 2011 to 2017. Based on the malaria biobank, 99.42% (2 223/2 236) of the blood smears and 82.74% (1 850/2 236) of DNA (from dried blood and whole blood samples) from malaria patients in Jiangsu Province were re-checked. Moreover, the samples in the malaria biobank were used in the studies of the mechanism of parasite drug resistance, malaria molecular epidemiology, and diagnosis technology development and evaluation. CONCLUSIONS: The establishment of malaria biobank provides a guarantee for malaria elimination in Jiangsu Province and also provides a qualified resource for malaria research.

[Progress in researches on molecular markers of non-Plasmodium falciparum drug resistance].

With the long-term and widespread application of antimalarial drugs, Plasmodium falciparum has gradually produced resistance to antimalarial drugs. At present, there are more researches on the molecular markers of P. falciparum drug resistance, while less attention has been paid to the molecular markers of non-P. falciparum drug resistance. In order to provide the reference for rational drug use in clinical treatment and reference for molecular monitoring of antimalarial drug sensitivity of non-P. falciparum, this paper reviews the researches on the common molecular markers related to non-P. falciparum drug resistance.

[Study on expression characteristics of cytochrome P450 genes in Anopheles sinensis].

OBJECTIVE: To explore the expression characteristics of cytochrome P450 (CYP) candidate genes (CYP6M3, CYP6Y1, CYP6P5, CYP4H14, CYP4G17, CYP12F16) in Anopheles sinensis. METHODS: The samples were collected from different developmental stages (eggs, larvae, pupae and adult mosquitoes (females and males) ), and different tissues (salivary glands, malpighian tubes, midguts, ovaries, and fat bodies) of An. sinensis and the female adult mosquitoes exposed by different insecticide doses (0, 1.25, 3.75, 6.25, 12.5 µg/bottle) and time points (0, 5, 15, 30, 60 minutes), then the total RNA was extracted. Quantitative reverse transcription PCR (qPCR) assay was used to analyze the relative expressions of six CYP genes in An. sinensis at different developmental stages, tissues and different insecticide exposure doses and time. RESULTS: The expressions of CYP6M3 and CYP6Y1 in the male adult mosquitoes were the highest, the expression of CYP6M3 gene in the males was 35.1 times higher than that in the females, the expression of CYP6Y1 in the males was 61.4 times higher than that in the females; the expression level of CYP4H14 in the larvae was the lowest, the expression of CYP4H14 in the females was 22.5 times higher than that in the fourth instar larvae. The expressions of candidate CYP genes in different tissues of An. sinensis were significantly different, the expression of CYP6M3 in the malpighian tubule was 38.9 times higher than that in the ovary, the expression of CYP6Y1 in the fatbody was 9.1 times higher than that in the ovary, the expression of CYP4G17 was 4.6 times higher than that in the ovary, and the expression of CYP12F16 was 4.4 times higher thanthat in the ovary. The exposure to different insecticide doses and time showed some induction effects in the expressions of candidate CYP genes, which affected the expressions of candidate CYP genes in An. sinensis. CONCLUSIONS: The expression of candidate CYP genes varies significantly in different developmental stages and various tissues of An. sinensis, and exposure to deltamethrin at various doses and time points affects CYP genes expression in An. sinensis.

[Results analysis of Jiangsu Provincial Malaria Diagnostic Reference Laboratory in 2017].

OBJECTIVE: To analyze the results of samples testing of Jiangsu Provincial Malaria Diagnostic Reference Laboratory in 2017, so as to provide the evidence for improving the malaria diagnostic performance in this province. METHODS: The samples of reported malaria cases in Jiangsu were collected by the provincial reference laboratory (PRL) in 2017. The microscopy and nucleic acid test were performed to confirm the infection of Plasmodium species of each case, while Plasmodium antigen tests (rapid diagnostic test, RDT) were performed as well. The detection results were analyzed among different areas and different species. RESULTS: Totally 242 malaria cases were reported and the samples were collected by PRL in 2017. A total of 239 cases were confirmed Plasmodium infections, including 163 cases of Plasmodium falciparum infection, 21 cases of P. vivax infection, 11 cases of P. malariae infection, 43 cases of P. ovale infection, and 1 case of P. falciparum and P. ovale mixed-infection. The diagnostic coincidence rates of reported malaria case in 13 prefectures with districts were all > 80%, and the total coincidence rate was 88.8%. The species diagnostic coincidence rates of P. falciparum, P. vivax, P. malariae, and P. ovale were 98.8%, 57.1%, 63.6%, and 81.4% respectively, and the detection rates by RDT to those four species infections were 95.7%, 85.0%, 63.6% and 79.1% respectively. CONCLUSIONS: In 2017, the malaria diagnostic quality of medical technicians is generally high in Jiangsu Province. However, the diagnostic capacity is slightly different among different regions, and the ability to identify non- P. falciparum parasites remains to be improved. RDT is not ideal for the detection of non-P. falciparum infection. In the current stage of malaria elimination, the malaria diagnostic capacity of technicians in all the sectors should be strengthened and maintained.

[Population structure and seasonal dynamics of mosquitoes in different types of residential areas].

OBJECTIVE: To investigate the effect of the type of neighborhoods on the population structure and dynamics of mosquitoes. METHODS: The adult population dynamics and larvae breeding of mosquitoes in four different types of neighborhoods were investigated in Yangzhou City. RESULTS: The number of trapped mosquitoes was the largest in the urban villages, and more than 800 adult mosquitoes were trapped in each urban village, which was significantly higher than that of ordinary and high quality residences. Aedes albopictus and Culex pipiens pallens were dominant species (D > 10%) in the four types of residential areas, and Ae. albopictus was the most dominant species (D > 57%). The peak occurrence of Ae. albopictus in different areas occurred in early June, and it occurred again in the urban village in the middle of September. The occurrence quantity of Cx. pipiens pallens was stable in the ordinary residence and high quality residence, while in the urban village and resettlement residential area, the peak occurred in mid-October. The orders of positive rates, densities and the numbers of mosquitoes in the different types of residential areas were：the urban villages> the resettlement residence> the ordinary residence> the high quality residence. The water vat had the highest positive rate in all kinds of larval habitats, followed by tires and green belt with garbage water. CONCLUSIONS: The main mosquito species in the four different types of residential areas are all Ae. albopictus and Cx. pipiens pallens, but the positive rate, density and the number of mosquitoes in the different types significantly change, especially in the urban villages, the number and the occurrence peak are significant different from those in the other types of residential areas.

Evaluating Diagnostic and Prognostic Value of Plasma miRNA133a in Acute Chest Pain Patients Undergoing Coronary Angiography.

Circulating microRNA has recently emerged as a promising biomarker for cardiovascular disease. This study sought to evaluate the diagnostic and prognostic value of circulating miR-133a as a marker of acute myocardial infarction in acute chest pain patients undergoing coronary angiography.Plasma was collected from 312 patients with chest pain on admission in the emergency department and 67 healthy controls. MiR-133a was detected using real-time quantitative PCR and enhanced accu-TnI, creatinine kinase-MB mass, and myoglobin were measured by immunoassay. End-point events (serious adverse cardiovascular events which require hospitalization or cardiovascular death) were examined in the AMI (acute myocardical infarction) group within 1, 6, 12, and 24 months.The miR-133a level was higher in AMI patients than in non-AMI patients (P < 0.001). In the ROC analysis, the sensitivity of miR-133a in diagnosis of AMI is 0.61 and the specificity is 0.68. In the prognostic analysis, only 1 endpoint event was observed in the non-AMI group; the amount of cases with end-point events in the AMI group at 1,6,12, and 24 months were 8, 19, 28, and 35, respectively. The cutoff value of miR-133a was determined using the median value of the AMI group and separated the patients into a positive group and a negative group. The Kaplan-Meier survival curve showed no significant difference in survival was detected in AMI patients between the miR-133a positive group and negative group after follow-up (12-month: x2 = 1.353, P = 0.245; 24-month: x2 = 3.722, P = 0.054). After adjusting for age, gender, Killip classes, prior myocardiac infarction history, myoglobin, LVEF (left ventricular ejection fraction), diabetes, hypertension, smoking and systolic blood pressure, miR133a had a significant association with the risk of events at 12 months (HR = 2.869, P = 0.024) and 24 months (HR = 3.936, P = 0.001).In patients undergoing coronary angiography, circulating miR-133a is upregulated in AMI patients, but it does not provide enough accuracy for clinical AMI diagnosis because it also rises in unstable angina patients. Its prognostic value in AMI is uncertain mainly for the number of cases with end-point event was small and may be further validated in a larger, better designed study.

[Evaluation of Wondfo Rapid Diagnostic Kit for detecting Plasmodium ovale and analysis of influencing factors].

OBJECTIVE: To evaluate the Wondfo Rapid Diagnostic Kit (Pf-LDH/Pan -pLDH) for detecting Plasmodium ovale and analyze the influence of parasitaemia, concentration and polymorphism of pLDH on the performances. METHODS: A total of 100 blood samples from P. ovale patients confirmed by PCR were detected with the Wondfo Rapid Diagnostic Kit according to the manufacturers'instructions. The parasitaemia was determined by the microscopic examination. The concentration of pLDH was measured by ELISA tests. The LDH gene of P. ovale was amplified by PCR and sequenced. The influence of these three factors on the positive rate was analyzed. RESULTS: The overall positive rate of Wondfo Rapid Diagnostic Kit was 70.0% (70/100). The positive rate was 27.3% for the samples with parasitaemia ≤ 500 parasites/µl and reached 75.0%-75.4% when parasitaemia > 500 parasites/µl. The positive rate was 6.7% for samples with a low pLDH concentration (A values ≤ 0.100) and reached 95.1%-100% at a high pLDH concentration (A values > 0.100). The results of sequence analysis indicated that all the samples could be divided into 2 types, P. o. curtisi and P. o. wallikeri. The gene homology of LDH between 2 types was 97%. There were 24 single nucleotide polymorphism (s) (SNPs) between 2 types, while only 3 SNPs were non-synonymous mutations. The homology of LDH amino acid sequences between 2 types was 99%; only 3 amino acids were different. The positive rates for P. o. curtisi and P. o. wallikeri were 73.1% (38/52) and 66.7% (32/48) respectively; there was no statistically significant difference (P > 0.05). CONCLUSIONS: The Wondfo Rapid Diagnostic Kit (Pf-LDH/Pan-pLDH) performs better than most of the similar products for the detection of P. ovale, and the positive rates are closely related to the parasitaemia and concentration of pLDH, while no related to the polymorphism of pLDH gene.

[Establishment of malaria early warning system in Jiangsu Province â § Malaria vector monitoring in Jiangsu Province].

OBJECTIVE: To understand the population, density, seasonal fluctuation and nocturnal pattern of malaria vectors in Jiangsu Province, thus to provide evidences for malaria elimination in this province. METHODS: Seven counties (cities, districts) were selected as the monitoring sites for malaria vectors in Jiangsu Province from 2013 to 2015. The mosquitoes were captured by human bait trapping in bed nets and mosquito-lured lamp overnight, and the seasonal fluctuation and nocturnal pattern of malaria vectors were observed. RESULTS: A total of 11 041 Anopheles sinensis mosquitoes were captured by the mosquito-lured lamps in 7 counties of Jiangsu Province from 2013 to 2015, and no An. anthropophagous was found. Among all the 7 monitoring sites, the number of An. sinensis captured in Sihong County was the most (6 742 mosquitoes), while that in Xuyu County was the least (34 mosquitoes). During this period, the density peaks of An. sinensis were the first half of July, the first half of August and the second half of July. A total of 2 421 An. sinensis were collected in 7 monitoring sites from 2013 to 2015 by human bait trapping in bed nets overnight. Among all the 7 monitoring sites, the captured number of An. sinensis in Sihong County was the most (1 085 mosquitoes), while that in Ganyu County was the least (13 mosquitoes). The nocturnal peak of An. sinensis was from 19：00 to 20：00 and 525 An. sinensis mosquitoes were captured during this period of time, which accounted for 21.68% of the total. Hereafter, the captured number of An. sinensis reduced over time. CONCLUSIONS: The density of An. sinensis mosquitoes is still high in individual areas in Jiangsu Province, so the epidemic and vector monitoring still should be strengthened to prevent the local transmission of imported malaria.

Establishment and characterization of dengue virus type 2 nonstructural protein 1 specific T cell lines.

Immunity against dengue viruses (DENV) infection may include cellular immune responses which involve in the immunopathology of DENV infection hosts. This study was to establish short-term dengue virus type 2 (DENV2) nonstructural protein 1 (NS1) specific T cells from splenocytes from BALB/c mice immunized with DENV2 NS1 in vitro, which may be used to identify immunopathologic mechanism of dengue. Nine DENV2 NS1 specific T cell lines were successfully established by using limiting dilution methods and maintained for 20 weeks by re-stimulated with DENV2 NS1, recombinant mouse IL-2 and antigen presenting cell weekly. Phenotypically, these cells were mainly composed of CD3(+)CD4(+) T cells. The culture supernatants of these cells contained large amounts of TNF-α and IFN-γ. Vascular tissue pathological change could be found in the mice adoptive transferred with DENV2 NS1 specific T cells. The results indicate that DENV2 NS1 specific T cells could be established and maintained with syngeneic T cell growth factors in vitro. Meanwhile, DENV2 NS1 specific T cells might contribute to the immunopathology of vascular leakage of dengue.